1. Field of the Invention
The invention pertains generally to a child resistant dispensing closure adapted to be associated with the neck of a container, bottle or other like receptacle. More particularly, the invention relates to a child resistant dispensing closure of the type comprising a cap base member and a cap lid member mounted upon the cap base member so as to be capable of assuming a closed position, wherein the contents of the container are prevented from passing through the dispensing closure, and an open position, wherein the contents are allowed to pass through the dispensing closure. According to the principles of the present invention, the cap lid member is provided with a locking prong for engaging locking means provided on the neck of the associated container in the closed position of the dispensing closure so as to positively secure the cap lid member in said closed position. The open position of the dispensing closure may be achieved only by manual manipulation of the dispensing closure in a series of separate dissimilar motions. The provision of the locking prong on the cap lid member and the locking means on the container neck, as well as the requirement for a combination of diverse actions in order to operate the dispensing closure, effectively precludes a child from gaining access to the contents of the container to which the dispensing closure is attached.
The term "dispensing closure" is commonly utilized to designate closures which are normally adapted for attachement to the necks of containers such as bottles, tubes, or the like. Such dispensing closures, as are commonly known, generally include a cap base member adapted to be secured to or formed integral with a container and a cap lid member which is mounted on the cap base member for movement between open and closed positions. In the open position, material can be moved through an opening in the cap base member, while in the closed position such opening is closed off or sealed.
It has been previously recognized that the utility of a dispensing closure in many different types of applications can be enhanced or improved by constructing such a closure so that the cap lid member is normally held in an open position once it has been moved into such position, until such time as deliberate force is applied by the user to close such a cap lid member.
Various expedients and structures have been utilized in the prior art in order to obtain the foregoing attributes. Examples of dispensing closures of this type are found in U.S. Pat. No. 4,172,540 and in U.S. Pat. No. 4,220,248. U.S. Pat. No. 4,172,540, issued on Oct. 30, 1979 to Erichson, discloses a dispensing closure having a cap base and a lid mounted thereon by means of a spring. The spring serves to hold the lid relative to the top of the cap base so that the lid is held against movement when in the open position. U.S. Pat. No. 4,220,248, issued on Sept. 2, 1980 to Wilson et al, is directed to a closure member and lid wherein a spring structure and a cam structure cooperate to hold the lid in an open or closed position.
The latter dispensing closure structures are considered to be highly desirable from a utilitarian standpoint in that the cap lid member is prevented from interfering with the discharge of material through such closures. Additionally, dispensing closures as so described may be easly and conveniently manufactured at a nominal cost and are of such a character that they afford facility of use over a prolonged period. Moreover, these dispensing closures are advantageous because of their simplicity, because the manner in which they are constructed makes it possible to utilize them without danger of damage during handling, installation and the like, and because they are aesthetically satisfying.
While the attributes of the foregoing dispensing closures are numerous, the need exists to provide such closures with an effective means for preventing unwanted access to potentially harmful contents of the container with which the closure is associated. The need for dispensing closures with child resistant features is precipitated by the extensive home and personal usage and consumption of potentially injurious substances such as medicaments, pharmaceuticals, cosmetics, cleaning preparations and the like. Thus, the need exists for a dispensing closure that not only possesses the diverse attributes discussed above, but which is capable of being positively and securely locked in the closed position so that comparatively young children or those of below-average mental capacity cannot open it under normal circumstances. The dispensing closure must be relatively difficult to open so as to remain inpenetrable to the often rigorous stresses and forces imposed upon it by an inquisitive and determined child. However, the dispensing closure must also be sufficiently easy to open so that it may be operated by individuals of average mental capacity, even if such individuals do not possess what may be regarded as normal physical strengths.
Previous attempts to provide dispensing closures of a child resistant character have often resulted in structures which, due to their complexity, were prohibitively expensive to manufacture for commercial utilization. Additionally, complicated construction often rendered the closure difficult to operate, even by an adult, requiring highly complicated manipulations and/or considerable force. Those closures wherein the child resistant feature depends upon the application of relatively great strength are particularly flawed in that a small child may be stronger than an elderly person or someone weakened by illness, and the closure therefore, inevitably fails to fulfill its child resistant purpose. The child resistant features which require unusually complex manipulations are, in reality, impractical to use and are destined to fail in gaining commercial acceptance. The more simple structures which have been adopted have generally proved to be disappointing in responding to child resistant demands, being easily penetrable, deliberately or inadvertently, by an average child.
The instant invention addresses the foregoing problems and deficiencies by providing a dispensing closure wherein the cap lid member is capable of being locked with respect to the neck of the attached container in the fully closed position of the dispensing closure and wherein the unlocked position of the dispensing closure is made possible only by manual rotation of the dispensing closure with respect to the associated container from the locked position so as to assume a specific limited position in which a locking prong on the cap lid member is disengaged from the neck of the container. The cap lid member is then able to be manually moved from the closed but unlocked position upwardly with respect to the cap base member to the fully open position wherein a dispensing opening provided in the cap base member is unobstructed, allowing the contents of the container to be dispensed therethrough. The cap lid member is normally maintained in the fully open position so as not to interfere with the dispensing of the container contents until such time as it is manually moved downwardly toward the cap base member to close or seal off the dispensing opening. The locking prong on the cap lid member is then engaged with the locking means on the neck of the associated container, thereby securing the dispensing closure against unwanted opening by a child.
The provision of a specific unlocked position for the dispensing closure with respect to the container neck, which unlocked position is available at only a very limited location, addresses the almost universal reaction exhibited by children in attempting to remove a closure from a container. More specifically, a child who is presented with the opportunity to explore a closed container will inevitably twist and rotate the attached closure in an effort to free the closure from the container or will attempt to separate the closure from the container by pulling the respective parts directly apart. Removal of the dispensing closure by rotation is prevented, due to the fact that the dispensing closure is positively secured to the neck of the container. The latter instinctive pulling motion is likewise ineffective to achieve opening of the dispensing closure of the present invention because the cap base member is positively and frictionally engaged with the neck of the associated container and cannot be pulled therefrom, even with the application of great force normally not possessed by a child. Additionally, the cap lid member is able to be pulled or lifted with respect to the cap base member only when the dispensing closure is specifically disposed with respect to the neck of the container in the unlocked position.
This unlocked position is very limited, with all other positions of the dispensing closure being locked positions, and is achieved only by exact rotation of the dispensing closure with respect to the neck of the container, thus requiring a degree of intellectual acuity beyond the ken of the normal child. A normal child is manifestly incapable of exercising the reason and intellect that is essential for accurately and properly rotating the dispensing closure to assume the unlocked position and thereafter, in an entirely dissimilar motion, to lift the cap lid member with respect to the cap base member. The manipulations characteristic of a child are inconsistent and random at best, thereby effectively precluding the possiblity that such individual could inadvertently or accidentally discover the unlocked position of the dispensing closure given the opportunity to manually rotate the closure with respect to the container.
Even were the unlocked position accidentally achieved and maintained, through lengthy and persistent rotation of the closure, actual opening of the cap lid member is possible only by thereafter applying an upward or lifting force to the cap lid member. This requirement for a secondary dissimilar action virtually insures against unwanted operation of the instant dispensing closure by a child in that a child is inherently incapable of engaging in the sophisticated mental and physical steps involved in making the transition from a manual rotational action to a manual lifting action. Indeed, the impatient nature of the typical child is likely to cause the child to abandon its unsuccessful efforts at twisting the dispensing closure in an effort to free it from the container after only a short while. The child can then be expected to utilize his teeth for purposes of prying the cap lid member from the cap base member. The instant dispensing closure is capable of rendering the latter efforts similarly ineffectual due to the fact that the cap lid member is lockingly engaged with the neck of the attached container in all rotational positions of the dispensing closure, except for the one very limited unlocked position. The possiblity that a child could inadvertently discover the specified unlocked position by rotating the closure, and then accidentally free the cap lid member by utilizing his teeth, is highly remote and, indeed, negligible. The series of movements required for operation of the present dispensing closure, intentional or otherwise, demand such coordination, dexterity and mental skill as are normally beyond the realm of capabilities of the ordinary child.
2. Description of the Prior Art
It is generally known in the prior art to provide a dispensing closure comprising a base portion to which a cap portion is hingedly connected. Moreover, it is generally known to provide such a dispensing closure with a locking member which is adapted to engage an internal portion of the base portion in the closed or sealed position of the dispensing closure.
For example, U.S. Pat. No. 3,603,470, issued on Sept. 7, 1971 to Armour, discloses a safety closure comprising an overcap having locking means which engages a groove located on the inner surface of the skirt of the closure. The locking means is released when an outwardly flaring section of the skirt is manually pressed.
U.S. Pat. No. 3,623,622, issued on Nov. 30, 1971 to Sullivan, shows a cap lid having a downwardly extending arm adapted to engage within an aperture in the wall of the base portion of the closure. The arm is withdrawn from the aperture when a lock disc on the lid is rotated.
It is also known in the prior art to provide a closure wherein locking means provided on the lid or cap member is adapted to engage an external portion of the closure base member. For example, U.S. Pat. No. 4,022,352, issued on May 10, 1977 to Pehr, is directed to a safety closure having a closure member provided with a latch member adapted to engage a portion of the exterior surface of a cap member. See also, U.S. Pat. No. Re. 29,973, issued on Oct. 3, 1978 to Pehr as a reissue of U.S. Pat. No. 4,022,352.
Similarly, U.S. Pat. No. 4,533,058, issued on Aug. 6, 1985 to Uhliq discloses a dispensing closure wherein a locking flap provided on the cap portion is adapted to be lockingly received in a recess formed in the skirt of the body portion. The closure is adapted to be opened by depressing the free end of the locking flap.
U.S. Pat. No. 4,629,081, issued on Dec. 16, 1986 to McLaren shows a closure having a cap, the locking bead of which is adapted to engage a trigger provided on the inner cap. Actuation of the trigger permits disengagement of the locking bead.
Moreover, the prior art teaches the concept of providing a closure wherein the lid carrier is formed with an opening for reception of a locking member provided on the lid. In particular, U.S. Pat. No. 4,244,495, issued on Jan. 13, 1981 to Lorscheid et al, teaches a safety closure including a lid and lid carrier, wherein the lid is provided with a locking member for reception and engagement within an opening in the lid carrier. The lid may be released by application of a manual force to a pressure surface on the lid carrier.
Additionally, the prior art teaches a variety of dispensing closures wherein locking means formed on the skirt of the closure engages with the associated container, whereby rotational movement of the closure is required in order to disengage same from the container.
An example of this type of closure is shown in U.S. Pat. No. 4,573,599, issued on Mar. 4, 1986 to Fillmore. Disclosed therein is a closure cap having a locking lug formed on the skirt of the cap for engagement with a retaining bead formed on the container. The closure cap is adapted to be removed by rotating the cap such that the locking lug is in alignment with a notch formed in the retaining bead.
Similalry, U.S. Pat. No. 4,071,156, issued on Jan. 31, 1978 to Lowe, is directed to a closure cap which has a series of locking lugs adapted to engage under a locking rib formed on the container neck in all positions except one, the cap being able to be freed from the container in said one position wherein the locking lugs are aligned with gaps formed in the locking rib.
Additionally, U.S. Pat. No. 3,980,194, issued on Sept. 14, 1976 to Costa discloses a cap having a skirt which is provided with a plurality of lugs adapted to underly a rib formed on the container neck. The cap is adapted to removed by rotating the cap such that one of the lugs is brought in alignment with a flattened portion of the rib.
U.S. Pat. No. 3,627,160, issued on Dec. 14, 1971 to Horvath, teaches a safety cap rotatably mounted on the neck of a container and having a lug for locking reception beneath a rib formed on the neck. The cap may be removed when the lug is brought into registry with a gap in the locking rib.
Finally, it is known in the prior art to provide a closure wherein the cap part is provided with locking means which engages the container and which is released by rotational movement. More specifically, U.S. Pat. No. 4,449,639, issued on May 22, 1984 to Davis is directed to a child resistant closure including a cap part provided with a lug for engaging an external projection on the rim of the container. Disengagement of the lug from the projection is accomplished by rotation of the cap part.
The prior art fails to teach or suggest a child resistant dispensing closure having a cap base member which is positively and securely associated with a container and which is operatively connected with a cap lid member having locking means, in the form of a locking prong, which, in the closed position of the closure, is adapted to be received within a slot formed in the cap base member and is adapted to engage a locking bead formed on the container. The prior art further fails to disclose a dispensing closure of this type wherein the cap lid member may be lifted to the open, or dispensing, position of the closure only when the locking prong is brought into alignment with a gap or interruption formed in the locking rib by rotating the closure with respect to the container, the locking prong being engaged beneath the continuous portion of the locking bead in all other positions of the closure.